<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>

  </style>
</head>

<body>
  <input id="app">

  <script>
    const oApp = document.querySelector('#app')


    function center() {
      console.log('我是核心函数');
    }

    oApp.onkeyup = throttle(center, 1000)

    function throttle(fn, time) {
      let timer = null
      return function (e) {
        clearTimeout(timer)
       timer = setTimeout(() => {
          fn.call(this, e)
        }, time)
      }
    }




  </script>
</body>

</html>